EVS-EN 62271-207:2007

This International Standard applies to switchgear assemblies for alternating current of rated voltages above 52 kV for indoor and outdoor installations, including their supporting structure rigidly connected to the ground, and does not cover the seismic qualification of live tank circuit breakers. Switchgear assemblies do have typically low centers of gravity, e.g. Gasinsulated switchgear (GIS). For switchgear with higher gravity levels, e.g. live tank circuit breakers, the IEC 62271-300 is applicable. Where switchgear assemblies are not ground-mounted, e.g. in a building, conditions for applications are subject to agreement between users and manufacturers. The seismic qualification of the switchgear assemblies takes into account any auxiliary and control equipment either directly mounted or as a separate structure. This standard provides procedures to seismically qualify ground-mounted switchgear assemblies for rated voltages above 52 kV. The seismic qualification of the switchgear assemblies is only performed upon request. This standard specifies seismic severity levels and gives a choice of methods that may be applied to demonstrate the performance of high-voltage switchgear assemblies for which seismic qualification is required. The final seismic analysis shall be performed by assuming that the switchgear is installed on firm ground.